Device for automatically separating a pair of yarn guiding rollers



Feb. 20, 1968 M. P. FONTELLAS 3,369,357

DEVICE FOR AUTOMATICALLY SEPARATING A I'AIR OF YARN GUIDING ROLLERS Filed June 1967 2 Sheets-Sheet l INVENTOR.

MANUEL PRAT FONTELILAS ATTORNEYS Feb. 20, 1968 M. P. FONTELLAS 3,369,357

DEVICE FOR AUTOMATICALLY SEPARATING A PAIR OF YARN GUIDING ROLLERS 2 Sheets-Sheet 23 Filed June 6, 1967 INVENTOR. MANUEL PRAT FONTELLAS his ATTORNEYS United States Patent 3,369,357 DEVICE FOR AUTOMATICALLY SEPARATiNG A PAIR OF YARN GUIDING ROLLERS Manuel Prat Fontellas, Avenida 28 de Enero 18, Balsareny, Barcelona, Spain Filed June 6, 1967, Ser. No. 643,869

Claims priority, application France, June 8, 1966,

64,697, Patent 1,504,508

Claims. (Cl. 57--84) ABSTRACT OF THE DISULOSURE The specification describes a device for automatically separating a pair of yarn guiding rollers which normally engage and feed the yarn but are mounted for separation in the event of breakage of the yarn. The device includes a pair of cams accommodated in grooves of one of the yarn guiding rollers and a yarn engaging pin carried between the cams. The yarn exerts a force on the pin which maintains the low portions of the cams between the rollers. In the event of breakage of the yarn the cams are frictionally driven by the rotating roller to bring the high portions thereof between the rollers to separate them.

This invention relates to a device for automatically separating a pair of yarn guiding rollers in the event of breakage of the yarn to prevent the further feed of the yarn and to facilitate rethreading the yarn in the machine.

In various machines, such as spinning, twisting and weaving machines, in which yarn or thread is fed by guiding rollers it is a difficult task to rethread the yarn in the machine after breakage of the yarn. Part of the difiiculty is the task of separating the guide rollers and then returning them to operative position after the flaw has been repaired and the yarn has been rethreaded in the machine.

The invention provides a device which automatically separates the yarn guiding rollers in the event of yarn breakage and thereby greatly facilitates the rethreading operation. In the device of the present invention one of a pair of guide rollers carries a cam frictionally connected with the roller so as to rotate therewith unless held in slipping relation with the roller. The cam has a gradually rising portion which protrudes beyond the periphery of the roller. The cam carries a yarn engaging means and the tension of the yarn against the yarn engaging means holds the cam against rotation with the roller and maintains the protruding portion of the cam away from the bite between the rollers. In the event of breakage of the yarn the restraining influence of the yarn on the cam is broken and the cam is frictionally car ried by the roller to wedge the high portion thereof between the rollers, thereby separating them automatically. With the guide rollers thus separated the rethreading of the yarn is greatly simplified, and when the rethreading has been completed and the break repaired the rollers are quickly restored into engagement with each other and the device reset so that the normal operation of the machine can be resumed.

For a complete understanding of the present invention reference can be made to the detailed description which follows and to the accompanying drawings, in which:

FIGURE 1 is a perspective view of one of the yarn guiding rollers grooved to receive the device of the present invention;

FIGURE 2 is a view of the yarn guiding roller equip ped with the present invention;

FIGURES 3 and 4 are perspective views of the cams used in the present invention;

FIGURE 5 is an elevational view of the yarn guiding rollers with the parts of the present invention in normal operating positions;

FIGURE 6 is a view similar to FIGURE 5 but showing the parts in position after separation of the rollers; and

FIGURE 7 is a perspective view illustrating another form of use of the present invention.

The present invention is shown applicable to a relatively short yarn guiding roller 10 which normally engages and is driven by a relatively long roller 11. In conventional twisting machines utilizing rollers of this type the supporting shaft 12 of the upper guide roller 10 is mounted to permit the roller 10 to be raised out of contact with the roller 11 to facilitate the threading of the yarn in the machine.

The yarn guiding roller 10 is provided with a pair of spaced apart grooves 13 and 14 each accommodating a cam 15 therein. The cams 1-5 have low portions 15a recessed within the respective groove, high portions 15b protruding outside the groove and beyond the outer periphery of the roller 10, the low portions gradually rising to the high portions, and tubular supports for receiving the ends of a cylindrical pin 16 connecting the cams. The pin 16 may serve as the yarn engaging means; in addition, it supports a pivotal element 17 thereon which carries a cylindrical yarn engaging pin 18.

The pivotal element 17, as best shown in FIGURES 2 and 7, is essentially a U-shaped piece which includes a cross-piece and two arms. One arm has a tubular formation 17a integrally formed at the end thereof for pivotal'ly connecting it to the pin 16. The other arm of the pivotal ement 17 rests against the bridging pin 16 but it is not connected to the pin to facilitate threading the yarn. The yarn engaging pin 18 carried by the pivotal element 17 is supported between the two arms. A yarn guiding channel 1% (see FIGURES 7) is defined in the crosspiece so that the moving yarn passes from engagement with the pin 18 through the open channel. 1712.

Although the parts can be of various materials and shapes, in the particular embodiment illustrated in the drawings the cams 15 are made of a resilient plastic material, such as nylon, and are split at 15d so that they can be opened by twisting, as shown in FIGURE 4, to permit them to be snapped into the grooves 13 and 14 of the yarn guiding roller 10. The pivotal element 17 can also be made of plastic, but it is preferable that the yarn engaging pins :16 and 18 be of smooth metal and cylindrical in shape.

The cams 15 are preferably balanced for relatively uniform weight distribution. Toward this end the portion of each cam opposite the tubular support 15c is of somewhat greater thickness and the high portion of the cam contains a series of openings 1 5e for better balance.

The yarn guiding rollers may be used in different ways. In one application, shown in FIGURE 5 and recommended for coarser yarns, the yarn y passes around the upper end of the guide roller 10, then between the rollers 16) and 11, passing over and in contact with both the pins 16 and 18 and then downwardly beneath the lower roller 11. In normal operation the tension of the yarn against the pins 16 and 18 holds the cams $15 in the position shown in FIGURE 5 to maintain the low portions thereof between the rollers. The low portions of the cams, being recessed within their respective grooves, permit the yarn guiding roller 10 to remain in pressure engagement with the lower roller 11.

Upon breakage of the yarn the cams are no longer held in the positions shown in FIGURE 5 but are frictionally carried by the guide roller 10, causing the high portions of the cams to wedge between the rollers, lifting the guide roller 10 out of contact with the roller 11 as shown in FIGURE 6. The frictional contact between the cams and the guide roller 19 is enough to rotate the cams and wedge the high portions thereof between the rollers 10, 11 to separate them but it is not enough to permit the high portions of the cams to pass between the rollers and permit the roller .10 to return into engagement with the roller 11. Instead the cams wedged between the rollers slip on the roller 11 after separating the roller 10 therefrom. With the rollers thus separated it is a comparatively simple matter for the operator to rethread the machine and correct the flaw in the yarn.

In another application of the present invention, illustrated in FIGURE 7 and recommended for finer yarns, the yarn passes twice between the same guide rollers with the assistance of a bent yarn guide 19. In this particular application of the invention, the yarn passes initially be tween the rollers 10 and 11 and around the portion of the roller 10 adjacent the groove 13, reversing its direction and returning to a U-shaped portion 19a of the guide 19. The yarn then passes around two vertical legs 1% and 19c of the guide 19, reversing its direction and bringing the yarn into alignment with the yarn engaging pins 18. The yarn then makes its second pass between the rollers 10 and 11, passes over the pin 18 and through the open channel 17b. The operation of the device used as illustrated in FIGURE 7 is precisely the same as has been described above upon breakage of the yarn.

The invention has been shown in a preferred form and by way of example only, and obviously many variations and modifications may be made therein without departing from the spirit of the invention. The invention therefore is not to be limited to any specified form or embodiment except insofar as such limitations are set forth in the claims.

I claim:

1. A device for automatically separating a pair of yarn guiding rollers which normally engage the yarn in tangential relation and are mounted for separation in the event of breakage of the yarn comprising at least one cam having a surface which rises gradually from the outer periphery of the roller and is connected to the roller in light frictional contact, and yarn engaging means carried by the cam to hold the cam in slipping relation with respect to the roller and in position to maintain the high portion of the cam away from the line of tangency between the rollers, the frictional connection between the cam and the respective roller rotating the cam with the roller to bring the high portion thereof between the rollers to separate them in the event of breakage of the yarn.

2. A device as set forth in claim 1 including means defining a groove in one of the rollers to accommodate the cam therein, the said cam having a low portion recessed within the groove and normally positioned between the rollers during normal operation, a high portion protruding outside the groove and beyond the periphery of the roller, and a portion gradually rising from the low portion to the high portion, the said cam at least partially encircling the roller in said groove.

3. A device as set forth in claim 1 which includes a pair of cams spaced apart on the respective roller and accommodated within grooves thereof and in which said yarn engaging means is supported between the said cams.

4. A device as set forth in claim 3 including means pivotally supported between the said cams and in which the yarn engaging means is carried by said pivotal means.

5. A device as set forth in claim 4 in which said pivotal means includes means defining an open channel through which the yarn passes after engaging the said yarn engaging means.

6. A device as set forth in claim 3 including a pin connecting the cams, means pivotally supported from the connecting pin, and a yarn engaging element carried by said pivotal means.

7. A device as set forth in claim 1 including a thread guide spaced apart from the guide rolls on the upstream side thereof and deflecting a span of the yarn returning from a first pass between portions of the guide rolls laterally offset from the yarn engaging means back toward the guide rolls and into a path in alignment with the yarn engaging means, the yarn passing over in contact with said yarn engaging means after the second pass through the yarn guiding rolls.

8. A device as set forth in claim 1 in which the cam is a split ring made of resilient material which permits the ring to be opened by twisting and snapped onto the groove in the respective yarn guiding roller.

9. A device as set forth in claim 1 including apertures in the high portion of the cam to balance the weight thereof and provide even weight distribution.

10. A device as set forth in claim 1 in which the yarn engaging means is a cylindrical pin having a smooth surface.

References Cited UNITED STATES PATENTS 3,063,229 11/1962 Bonel 57-84 3,074,606 1/ 1963 Kieronski 22611 3,260,043 7/ 1966 Anselmetti 5784 FOREIGN PATENTS 504,054 4/1939 Great Britain.

JOHN PETRAKES, Primary Examiner. 

